There are a variety of technologies seeking to provide methods of detecting biological analytes in a sample. For example, U.S. Pat. Nos. 6,361,944, 6,506,564, 6,750,016 and 6,767,702 disclose a method of detecting nucleic acid by observing a change in color when oligo-nucleotides are hybridized to the nucleic acid. Yguerabide et al (Journal of Cellular Biochemistry Supplement 37:71-81 (2001)) discloses the use of resonance light scattering (RLS) particle as labels for analyte detection. Foultier et al (IEE Proc.-Nanobiotechnol., Vol. 152, No. 1, February 2005) discloses the use of fluorescent label technologies in visually detecting the presence or absence of a target analyte in a sample. Despite the availability of these various methods, it has been found that detecting biological analyte by optical means is often unsatisfactory. The present invention seeks to provide an improved method to address this issue, or at least an alternative to the public.